Am.  Jour.  Pharm. 
Nov.,  1893. 
Oils  of  Anise. 
541 
a  few  degrees  higher  than  the  normal  solidifying  point,  and  in 
recent  samples  may  vary  from  6o°  to  68°  F. 
It  must  be  noted,  however,  that  the  congealing  point,  in  what- 
ever way  taken,  is  not  of  much  value  either  as  a  character  or  test, 
except  for  fresh  oil,  as  it  becomes  lower  on  keeping  at  a  rate  differ- 
ing in  each  sample.  I  have  had  specimens,  the  melting  point  of 
which  after  two  years  had  only  been  reduced  50  to  70  F.,  while  other 
(both  from  ordinary  and  star  anise),  after  a  similar  interval,  and 
kept  under  roughly  similar  conditions,  could  not  be  made  to  freeze  at 
io°  F.  Whether  these  differences  are  due  to  the  larger  proportion 
of  the  anise  terpene  accelerating  the  oxidation  of  the  anethol  I  have 
not  yet  determined  experimentally. 
The  specific  gravity  depends,  (1)  on  the  proportion  of  terpene 
•870,  then  10  20,  and  25  per  cent,  of  terpene  will  give  specific  gravi- 
ties or  -996,  -982,  and  -975,  respectively,  which  covers  the  maximum 
and  minimum  of  fresh  oils  as  generally  met  with  ;  (2)  on  the  oxida- 
tion of  the  anethol  into  anisic  aldehyde,  the  published  sp.  gr.  of 
which  is  moo.  Of  the  oils  examined,  the  highest  specific  gravity 
which  we  have  noted  is  1-105,  being  the  last  few  ounces  of  a  bottle 
of  English-distilled  oil  from  ordinary  anise,  so  that  according  to  the 
age  of  the  oil  we  may  have  any  sp.  gr.  between  -975  and  i-ioo. 
The  polarizing  rotation  of  anise  oils  in  a  200  mm.  tube  has  in  the 
samples  examined  varied  between  +2^°  and  — 4^  °.  It  is  usually  a 
small  minus  quantity  ;  appears  to  have  no  connection  with  the  source 
of  the  oil;  does  not  alter  in  a  year;  and  is  greater  in  the  liquid 
portion  of  the  oil  than  in  the  solid.  Pure  anethol  has  probably  no 
rotation  whatever. 
Anethol  requires  for  solution  three  parts  of  rectified  spirit  and 
200  parts  of  proof  spirit.  As  oxidation  proceeds,  the  solubility 
increases,  till  the  oil  mixes  with  rectified  spirit  in  all  proportions 
and  dissolves  in  about  1 00  parts  of  proof  spirit.  Star  anise  oil, 
however,  appears  to  contain  a  small  quantity  of  some  constituent 
insoluble  in  proof  spirit,  as  even  after  warming  the  solution  is 
slightly  turbid. 
Eykmann's  test  is  understood  by  Mr.  Umney  {Ph.  J.,  [3],  xix, 
649)  to  be  "  a  saturated  solution  of  hydrochloric  acid  gas  in  absolute 
alcohol,"  and  is  stated  by  him  to  give  with  "  pimpinella  "  oil  a  man- 
ganese-pink color,  and  with  star  anise  oil  a  yellowish-brown  color. 
In  the  1890  edition  of  the  "  Companion,"  however,  we  mentioned 
